BRCA1 and BRCA2 are associated with breast and ovarian tumors. HNPCC gene alterations are associated with colorectal cancer. Cowden disease is associated with breast cancer but is not associated with sarcomas or leukemias. Li-Fraumeni syndrome is caused by mutations in the gene for tumor protein p53 and is associated with leukemias, lymphomas, sarcomas, and breast cancer.6
REFERENCE 6. Lindblom A. Familial breast cancer and genes involved in breast carcinogenesis. Breast Cancer Res Treat 1995;34:17183.